#board {
    position: relative;
    margin: 10px auto 10px auto;
    width: 535px;
    height: 535px;
}

.board_block {
    border-style:none;
    position: absolute;
    width: 35px;
    height: 35px;
    z-index: 11;
    opacity: 0;
}

.board_block.active {
    width: 34px;
    height: 34px;
    border-radius: 49%;
    /*box-shadow: 2px 2px 5px #333333, 2px 2px 5px #333333;*/
    opacity: 1;
}

.board_block.active.white {
    background: rgb(255,255,255);
    background: radial-gradient(ellipse at 70% 30%, rgba(255, 255, 255, 0.98) 0%, rgba(255, 255, 255, 0.98) 90%, rgb(189, 189, 189) 100%);
}

.board_block.active.black {
    background: rgb(0, 0, 0);
    background: radial-gradient(ellipse at 70% 30%, #45484d 1%, #000000 100%);
}

#buttons {
    position: relative;
    margin: 10px auto 10px auto;
    width: 420px;
    height: 60px
}

#start {
    line-height: 0;
}

#resign {
    line-height: 0;
}

#retract {
    line-height: 0;
}